Genes shown to influence disease course in MS.
A number of genes have been shown to change a person’s risk of getting MS, but there haven’t been any genes found that influence whether a person has aggressive or mild disease. Now a new study has identified three genetic changes that seem to be related to disease course.
Genetic research in MS has a long and successful history, with more than 200 genetic changes that can influence the risk of developing MS having been identified. Genetic research provides a lot of information about the nature of MS right down at a molecular level, and reveals which biological pathways are involved in disease.
Unfortunately, one area where genetic research in MS has been less successful is discovering genes that influence disease course. In other diseases, genes often control disease course, dictating the ultimate severity of the disease. If we knew this information for MS, we could predict the type of disease that a person will experience and this in turn could potentially help to guide treatment choices. For example, a person who was predicted to have more active disease may choose a more aggressive therapy early in the disease course.
A new comprehensive study may now have found some elusive genes that seem to be related to disease course in MS. The researchers compared the genes of people with benign MS and people with aggressive MS. People with benign MS had less disability (a score of three or lower on the EDSS or extended disability severity score) after 15 years or more, and had never received any MS treatment. Those with aggressive disease had accumulated more disability (a score of 6 or more on the EDSS) in the first five years of having MS, despite being treated for MS. The researchers looked across all the genes in the genome, specifically in regions of the DNA which encode the instructions to make proteins. These parts of the DNA have traditionally been thought to be more likely to play a role in disease progression.
Published in Journal of Neuroinflammation, the study initially identified 16 genetic changes that were different depending on whether participants had benign or aggressive MS. The scientists then focused on three genes, called IGSF9B, NLRP9 and CPXM2. Changes in the first two genes were associated with benign MS and changes in the last one was associated with aggressive forms of MS.
To help identify how these genes were influencing the course of disease, the scientists looked at the activity of each of the genes in different parts of the body, and unlike some of the risk genes which are active in the immune system, these genes appeared to be active in brain tissue. The researchers suggest that the genetic changes may be affecting specific cell types within the brain altering the course of disease in people with MS. These genes may also provide vital clues about which biological pathways are responsible for disease course in MS.
MS is an unpredictable disease and people with MS often say that the unpredictability is one of the hardest aspects of the disease to deal with. Identifying genes such as the ones found in this study may eventually allow medical teams to predict outcomes in people with MS and tailor treatment and advice accordingly in the clinic.